Articulated center post

ABSTRACT

This invention relates to an occlusion device for the heart, having an articulated center post which prevents rotation of the individual occluder elements around the center post, while allowing the device to better conform to the contours of the heart to increase sealing abilities and reduce breakage resulting from conformation pressure.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation-in-part of U.S. application Ser. No.10/348,865, filed Jan. 22, 2003.

BACKGROUND OF THE INVENTION

This invention relates to an occlusion device for the closure ofphysical apertures, such as vascular or septal apertures. Morespecifically, this invention relates to an occlusion device for theheart, having an articulated center post which allows the device tobetter conform to the contours of the heart.

Normally, permanently repairing certain cardiac defects in adults andchildren requires open heart surgery, a risky, expensive, and painfulprocedure. To avoid the risks and discomfort associated with open heartsurgery, modern occlusion devices have been developed that are small,implantable devices capable of being delivered to the heart through acatheter. Rather than surgery, a catheter inserted into a major bloodvessel allows an occlusion device to be deployed by moving the devicethrough the catheter. This procedure is performed in a cardiac cathlaband avoids the risks and pain associated with open heart surgery. Thesemodern occlusion devices can repair a wide range of cardiac defects,including patent foramen ovale, patent ductus arteriosus, atrial septaldefects, ventricular septal defects, and may occlude other cardiac andnon-cardiac apertures.

There are currently several types of occlusion devices capable of beinginserted via a catheter including button devices, collapsibleumbrella-like structures, and plug-like devices. A potential draw backto these devices is the difficulty in ensuring that the occluderconforms to the contours of the defect. Poor conformation to the defectresults in poor seating of the device which decreases the ability of thedevice to occlude the defect. Ensuring the proper seating of anocclusion device once it has been deployed poses a continuing challengegiven the uneven topography of the vascular and septal walls of eachpatient's heart. The challenge in designing an occluder which conformsto the uneven topography is compounded by the fact that the contours ofeach defect in each individual patient are unique.

Lack of conformation to the walls of the heart can place significantamounts of stress on the occlusion device and decrease fatigue life.Once deployed, different parts of the occluder may experience more orless stress as a result of the uneven topography. At some point,stressed parts of the occluder may break. Broken parts increase thelikelihood of damage to the surrounding tissue and lead to patientanxiety.

Another obstacle which maybe encountered is the difficulty in readilydistinguishing the individual occluder elements in order to determinetheir position in relation to each other and allow for repositioning,while still maintaining the flexibility needed for better conformation.

Thus, there is a need in the art for an occlusion device that willocclude cardiac defects and will match the contours of the heart therebyincreasing the life of the device and sealing ability while reducingdamage to the surrounding tissue. There is also a need for an occlusiondevice that prevents rotation of the individual occluder elements aroundthe center post, while still maintaining the needed flexibility toproperly position the device and successfully match the contours of theheart.

BRIEF SUMMARY OF THE INVENTION

The present invention allows occlusion devices to more effectively closea physical anomaly. The present invention is an occlusion device havinga first occluding body, a second occluding body, and an articulatedcenter section. The articulated center section increases the ability ofthe occlusion device to more accurately conform to the defect.

The center section includes a ball and socket joint and means forlimiting rotation of the first occluding body relative to the secondoccluding body. The means for limiting rotation of the first occludingbody relative to the second occluding body includes interlockingelements. In a first embodiment, the interlocking elements include a pegon a ball of the ball and socket joint and a groove on a socket of theball and socket joint. In a second embodiment, the interlocking elementsinclude a groove on a ball of the ball and socket joint and a peg on asocket of the ball and socket joint. The occluding bodies arerotationally limited but are still able to articulate, which allows foreasier positioning of the occlusion device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an occlusion device with an articulatedcenter post.

FIG. 2 a is a diagram of a heart with a septal defect.

FIG. 2 b is a diagram of an occlusion device being inserted into adefect.

FIG. 2 c is a diagram of an occlusion device with an articulated centersection being inserted into a defect.

FIG. 2 d is a diagram demonstrating the conformation capabilities of anocclusion device with an articulated center.

FIG. 3 a is a side view of an articulated center section having twojoints.

FIG. 3 b is a side view of an articulated center section having threejoints.

FIG. 4 is a side view of an articulated center section.

FIG. 5 a is a side view of a first embodiment of a second center postwith rotation-inhibiting capabilities.

FIG. 5 b is a perspective view of a first embodiment of a second centerpost with rotation-inhibiting capabilities.

FIG. 6 is a side view of a first embodiment of a first center post withrotation-inhibiting capabilities.

FIG. 7 a is a side view of a second sleeve.

FIG. 7 b is a perspective side view of a first embodiment of the secondsleeve with rotation-inhibiting capabilities.

FIG. 8 is a side view of a first sleeve.

FIG. 9 is a cross sectional view of an assembled articulated centersection combining the first embodiment of a center post withrotation-inhibiting capabilities and the first embodiment of a sleevewith rotation-inhibiting capabilities.

FIG. 10 is a sectional view of the center section along section 10-10 ofFIG. 9.

FIG. 11 is a perspective side view of a second embodiment of a centerpost with rotation-inhibiting capabilities.

FIG. 12 shows a cross sectional view of an assembled articulated centersection combining the second embodiment of a center post withrotation-inhibiting capabilities and the second embodiment of a sleeveof a center connector with rotation-inhibiting capabilities.

FIG. 13 is a sectional view of the center section along section 13-13 ofFIG. 12.

DETAILED DESCRIPTION

FIG. 1 is a top perspective view of occlusion device 10. As viewed inFIG. 1, occlusion device 10 comprises center section 12, proximalfixation device 14, six arms 16, atraumatic tips 18, proximal sheet 20,distal sheet 22, knob 24, sutures 28, and distal fixation device 30.Proximal and distal fixation devices 14, 30 are attached to sheets 20,22 using sutures 28. Proximal and distal fixation devices 14, 30 areconnected to center post 12. One method of connecting arms 16 to centersection 12 is to provide center section 12 with drill holes throughwhich arms 16 extend. Atraumatic tips 18 are located at the distal endof each arm 16 and serve to minimize damage to the surrounding tissue.Atraumatic tips 18 provide a place for sutures 28 to attach sheets 20,22 to proximal and distal fixation devices 14, 30. One method ofsuturing sheets 20, 22 to proximal and distal fixation devices 14, 30 isto provide atraumatic tips 18 with drill holes through which sutures 28pass. In this way, sheets 20, 22 are sewn to fixation devices 14, 30 atatraumatic tips 18. More specifically, occlusion device 10 isconstructed so that proximal and distal fixation devices 14, 30 areeasily collapsible about center section 12. Due to this construction,occlusion device 10 can be folded so that fixation devices 14, 30 arefolded in the axial direction. Proximal and distal sheets 20, 22, whichare attached to proximal and distal fixation devices 14, 30 areflexible, and can likewise collapse as proximal and distal devices 14,30 are folded. In addition, center section 12 further comprises knob 24.Knob 24 allows for occlusion device 10 to be grasped as it is insertedinto the body through the catheter.

Once occlusion device 10 is deployed, fixation devices 14, 30 serve tohold proximal and distal sheets 20, 22 in place to seal the defect. Toensure there is sufficient tension to hold sheets 20, 22 in place,fixation devices 14, 30 are made of a suitable material capable of shapememory, such as nickel-titanium alloy, commonly called Nitinol. Nitinolis preferably used because it is commercially available, very elastic,non-corrosive, and has a fatigue life greater than that of stainlesssteel. To further ensure that fixation devices 14, 30 do not suffer fromfatigue failures, one embodiment of the present invention relies onmaking fixation devices 14, 30 of stranded wire or cables.

Center section 12 shown in occlusion device 10 is articulated. Thearticulation can be accomplished by a variety of methods. Thearticulation could comprise one or more joints, or hinges. It could alsobe a spring or a coil. Additionally, a spot specific reduction in theamount of material used to create center section 12 could renderportions of center section 12 sufficiently flexible.

Center section 12 is preferably formed to have a diameter of betweenabout 8 millimeters and about 0.1 millimeters. In addition, the lengthof center section 12 is preferably less than about 20 millimeters.

Sheets 20, 22 are comprised of a medical grade polymer in the form offilm, foam, gel, or a combination thereof. One suitable material isDACRON®. Preferably, a high density polyvinyl alcohol (PVA) foam isused, such as that offered under the trademark IVALON®. To minimize thechance of occlusion device 10 causing a blood clot, foam sheets 20, 22may be treated with a thrombosis inhibiting material. One such suitablematerial is heparin.

The size of sheets 20, 22 may vary to accommodate various sizes ofdefects. When measured diagonally, the size of sheets 20, 22 may rangefrom about 15 millimeters to about 45 millimeters. In some instances, itmaybe desirable to form sheets 20, 22 so that they are not both the samesize. For instance, one sheet and its associated fixation device can bemade smaller (25 millimeters) than the corresponding sheet and itsassociated fixation device (30 millimeters). This is particularly usefulin situations where occlusion device 10 is to be placed at a location inthe heart which is close to other nearby cardiac structures. Makingsheets 20, 22 different sizes may assist in providing optimal occlusionof a defect, without affecting other structures of the heart which maybe nearby.

FIGS. 2 a-2 d illustrate the method by which occlusion device 10 isdeployed. FIG. 2 a is a diagrammatic view of human heart 31. Shown inFIG. 2 a is right atrium 32, left atrium 34, right ventricle 36, leftventricle 38. Right atrium 32 is separated from left atrium 34 by atrialseptal wall 40. Right ventricle 36 is separated from left ventricle 38by ventricular septal wall 42. Also visible in FIG. 2 a is atrial septaldefect 44 located in atrial septal wall 40, between right atrium 32 andleft atrium 34 of heart 31. Atrial septal defect 44 is one example of acardiac defect that may be occluded using occlusion device 10.

FIG. 2 b illustrates occlusion device 10 being inserted into a septaldefect. Shown is center section 12, right atrium 32, left atrium 34,septal wall 40, septal defect 44, catheter 50, and delivery forceps 52.As viewed in FIG. 2 b, occlusion device 10 comprises distal side 54,proximal side 56, and center section 12. Occlusion device 10 is beinginserted into septal defect 44 from catheter 50. Occlusion device 10 istethered to delivery forceps 52. To insert occlusion device 10, catheter50 is positioned proximate septal defect 44. Next, delivery forceps 52is used to push occlusion device 10 through catheter 50 so that distalside 54 of occlusion device 10 unfolds in left atrium 34. Althoughdistal side 54 has been deployed, proximal side 56 is still folded incatheter 50.

The placement of catheter 50, or other means that guides occlusiondevice 10 to septal defect 44, determines the location of and angle atwhich occlusion device 10 is deployed. Once catheter 50 is properlypositioned at septal defect 44, delivery forceps 52 is used to pushocclusion device 10 through septal defect 44. Distal side 54 ofocclusion device 10 is then allowed to expand against septal wall 40surrounding septal defect 44.

In FIG. 2 b, center section 12 is articulated but the articulationremains inside catheter 50 and is therefore immobilized. If centersection 12 of occlusion device 10 is not articulated (or articulated butimmobilized), center section 12 must enter septal defect 44 followingthe same angle of insertion as catheter 50 or other delivery device. Asa result, the insertion angle is limited by the catheter's angle ofinsertion.

Often, due to limited space, catheter 50 enters the heart at an anglethat is not perpendicular to the defective wall. In this situation,occlusion device 10 cannot enter septal defect 44 properly because theline of center section 12 must follow the same line as catheter 50.Occlusion device 10 must be forced into septal defect 44 at an angle,which may cause the tissue surrounding defect 44 to become distorted. Ifthe surrounding cardiac tissue is distorted by catheter 50, it isdifficult to determine whether occlusion device 10 will be properlyseated once catheter 50 is removed and the tissue returns to its normalstate. If occlusion device 10 is not seated properly, blood willcontinue to flow through septal defect 44 and occlusion device 10 mayhave to be retrieved and re-deployed. Both doctors and patients preferto avoid retrieval and re-deployment because it causes additionalexpense and longer procedure time.

FIG. 2 c shows occlusion device 10 with articulated center section 12being inserted into defect 44. Shown once again is occlusion device 10,septal wall 40, defect 44, catheter 50, distal side 54, and proximalside 56. Also, shown is joint 62. In FIG. 2 c, occlusion device 10 hasbeen further advanced through catheter 50 to expose articulated centersection 12 comprising joint 62.

When center section 12 is articulated or flexible, the insertion angleof occlusion device 10 is not restricted to that of catheter 50.Occlusion device 10 can be more easily inserted, because once joint 62is outside catheter 50, the angle of insertion can be changed byallowing joint 62 to move. This variable insertion angle allowsocclusion device 10 to enter defect 44 at an optimum angle, minimizingdistortion of surrounding cardiac tissue. If the tissue is not distortedwhen occlusion device 10 is deployed, the seating of occlusion device 10should not change drastically once catheter 50 is removed. Becauseocclusion device 10 can be properly seated at the first insertion, thenumber of cases that require retrieval and redeployment should decrease.

FIG. 2 d shows occlusion device 10, which is fully deployed and isoccluding defect 44. Shown in FIG. 2 d is articulated center section 12,septal wall 40, defect 44, distal side 54, proximal side 56, and joint62. Distal side 54 has been properly positioned, proximal side 56 hasbeen deployed and occlusion device 10 has been released. FIG. 2 d alsodemonstrates the ability of occlusion device 10 with articulated centersection 12 to conform to an irregularly shaped defect 44.

Another important advantage of the present invention is that articulatedcenter section 12 allows distal and proximal sides 54, 56 to conformmore readily to the contours of a heart after it is deployed, providinga custom fit to a variety of defects. Often, when implanted, occlusiondevice 10 is located in an irregularly shaped defect. Having articulatedcenter section 12 allows occlusion device 10 to conform to a broaderspectrum of defects.

For instance, as viewed in FIG. 2 d, septal wall 40 on the bottom ofseptal defect 44 may be only a few millimeters thick, but septal wall 40on the top of septal defect 44 may be much thicker. In such cases, oneside of occlusion device 10 may be bent open further than the otherside. The side that is more distorted carries a high static load whichincreases pressure on the surrounding tissue and also increases thepossibility of breakage If center section 12 is articulated, it can bendsuch that proximal and distal fixation devices 14, 30 need not be theonly the only parts which adjust to fit septal defect 44. The ability toconform to a variety of heart contours results in better seating,reduces tension (increasing fatigue life), and decreases the likelihoodof damage to tissue resulting from breakage and from pressure exerted onsurrounding tissue.

Another feature of occlusion device 10 is that it is fully retrievable.To allow occlusion device 10 to be retrievable, as well as ensure thatocclusion device 10 fits into a small diameter catheter, it is importantto ensure that arms 16 are not of a length that results in atraumatictips 18 clustering at the same location. If atraumatic tips 18 allcluster at the same location when occlusion device 10 is inside catheter50, occlusion device 10 will become too bulky to allow it to be easilymoved through catheter 50.

In situations where occlusion device 10 is not properly deployed andmust be retrieved into catheter 50, it is possible to withdraw occlusiondevice 10 back into catheter 50 by grasping either center section 12 orby grasping any arm 16. When occlusion device 10 is retrieved intocatheter 50, both upper and lower arms 16 will be folded in the samedirection. Once again it is important to vary the length of upper andlower arms 16, so that when occlusion device 10 is retrieved,atraumantic tips 18 on upper arms 16 do not cluster at the same locationas atraumatic tips 18 on lower arms 16.

FIG. 3 a is a perspective view of articulated center section 70, whichhas double articulation. Shown in FIG. 3 a is knob 24, articulatedcenter section 70, first center post 72, second center post 74, centerconnector 76, joints 78, and holes 80. As viewed in FIG. 3 a, centersection 70 comprises first center post 72, second center post 74, andcenter connector 76. Knob 24 is located on second center post 74. Bothfirst and second center posts 72, 74 have three holes 80 drilled throughthem. Center section 70 further comprises two joints 78 which arelocated on each end of center connector 76. Joints 78 connect first andsecond center posts 72, 74 to center connector 76 and allow for firstand second center posts 72, 74 to rotate relative to center connector76. Wire arms 16 (FIG. 1) attach to center section 70 bypassing throughholes 80 drilled through first and second center posts 72, 74.

In this example, joint 78 provides the articulation. Though shown withdouble articulation, articulated center section 70 is not so limited.The number of joints 78 may be varied to accommodate a particular defector a particular type of defect. For example, one joint may be best foran atrial septal defect while two or three articulations may be best fora larger defect such as patent foramen ovale or a long defect such aspatent ductus arteriosus.

FIG. 3 b is a side view of articulated center section 90 with triplearticulation, which demonstrates the broad range of flexibilitypossible. Shown is knob 24, holes 80, first center post 92, secondcenter post 94, two center connectors 96, joining part 98, and threejoints 100. The large amount of flexibility allows the occlusion deviceto conform to a wide variety of defects.

FIG. 4 is an enlarged side view of articulated center section 70,showing center section 70 in more detail. Shown is knob 24, first centerpost 72, second center post 74, center connector 76, first sleeve 112,second sleeve 114, and two joints 116, 118.

First sleeve 112 and second sleeve 114 comprise center connector 76.Second center post 74 connects to center connector 76 by joining secondsleeve 114 at joint 116. First center post 72 connects to centerconnector 76 by joining first sleeve 112 at joint 118. When theocclusion device is fully assembled, occluder elements will be attachedto first and second center posts 72, 74, as can be seen in FIG. 1.

There are several disadvantages to allowing the occluder elements torotate around the articulated center post. First, it is possible thatthe support arms of one support frame will line up with the arms of theother support frame, making it difficult to distinguish one set from theother set when the occlusion device is viewed on a fluoroscope. As aresult, it is more of a challenge to determine the exact position ofeither support frame because when aligned, the two becomeindistinguishable.

Secondly, preventing rotation of the occluder elements may improve theoverall positioning of the device. For example, when inserting a devicethat allows freedom of rotation, if upon the insertion of the device,the arms of a support frame are laying in an undesirable position, suchas resting against the aorta, simply manipulating the device toreposition the arms may not be possible because the center post willrotate consistently relative to the occluder element, leaving the armsin the original position.

Finally, the preliminary loading of the device may be hindered ifrotation of the support frames is not prevented. When the individualoccluder elements rotate consistently, loading the occlusion device intoa delivery device or catheter may be more difficult and time-consuming.

FIG. 5 a is a side view of a first embodiment of second center post 74with rotation-inhibiting capabilities. Shown is knob 24, three holes 80,second center post 74, head 120, first neck 122, body 124, second neck126, and pegs 138 a-c. Peg 138 d cannot be seen from this perspective.As described with reference to FIG. 1, three holes 80 are drilledthrough second center post 74 to allow for attachment of wire arms 16.

Head 120 located at a first end of second center post 74 is connected tobody 124 of second center post 74 at first neck 122. Knob 24 is locatedon the second end of body 124 and is connected to body 124 by secondneck 126. To assist in assembly, which is discussed in more detailbelow, the body 124 of second center post 74 is preferably smaller indiameter than head 120. Knob 24 has a smaller diameter than both body124 and head 120. For example, head 120 may have a diameter A of about1.35 millimeters, body 124 may have a diameter B of about 1.2millimeters, and knob 24 may have a diameter C of about 1.0 millimeter.

Knob 24 is configured to allow a delivery forceps to attach to occlusiondevice 10 as it is pushed through a catheter and allows the forceps tomanipulate occlusion device 10 as it is delivered. Likewise, a guideforceps can be used to position occlusion device 10 once it reaches thedesired location or to retrieve occlusion device 10 should it not beseated properly. Knob 24 may additionally have a cross sectional areawhich allows the forceps to rotatably move occlusion device 10 whileocclusion device 10 is inserted into septal defect 44. Second neck 126is grasped by a forceps so that there is at least some play between theforceps and second neck 126 when pushing occlusion device 10 through acatheter. For example, the guide forceps may engage second neck 126 bymeans of a claw-like or hook-like end. In an alternate embodiment, knob24 is threaded to allow for attachment to a threaded guide forceps.

FIG. 5 b is a perspective side view of the first embodiment of secondcenter post 74 with rotation-inhibiting capabilities. Shown is knob 24,center post 74, holes 80, head 120, first neck 122, body 124, secondneck 126, and pegs 138 a-138 d.

In this embodiment, head 120 includes pegs 138 a-138 d positioned aroundits circumference. Pegs 138 a-138 d are shown evenly spaced to providearticulation about two orthogonal axes when coupled with a centerconnector, as described in detail in FIG. 9.

FIG. 6 is a perspective view of a first embodiment of first center post72 with rotation-inhibiting capabilities. Shown is first center post 72,three holes 80, head 130, first neck 132, body 134, and pegs 138 a-138c. Peg 138 d cannot be seen from this perspective. Once again, threeholes 80 are drilled through first center post 72 to allow forattachment of wire arms 16.

First center post 72 is nearly identical to second center post 74 exceptthat it does not include knob 24 or second neck 126. Because occlusiondevice 10 only needs to be graspable at one end, a second knob isunnecessary. To assist in assembly, body 134 of first center post 72 ispreferably smaller in diameter than head 130. For example, head 130 mayhave a diameter D of about 1.35 millimeters, and body 134 may have adiameter E of about 1.2 millimeters.

Preferably, a hard metal, such as titanium, is used to construct centerposts 72, 74 because use of a hard material prevents binding within thejoints when the center section if fully assembled. Pegs 138 a-138 d maybe machined directly into the titanium, using a process such aselectrical discharge machining.

Although in FIGS. 5 a-6, heads 120, 130 are shown with four pegs 138a-138 d, the present invention is not so limited. Heads 120, 130 mayinclude any number of pegs, including as few as one peg.

FIGS. 7 a and 7 b show side and perspective views of second sleeve 114.FIG. 7 b shows sleeve 114, channel 139 a, and socket 152. Channels 139b-139 d cannot be seen from this perspective. Channels 139 a-139 d maybe machined directly into the titanium, using a process such aselectrical discharge machining.

The number of channels 139 a-139 d formed in socket 152 corresponds tothe number of pegs 138 a-138 d formed on head 120. Pegs 138 a-138 d andchannels 139 a-139 d are identically spaced, which allows for pegs 138a-138 d and channels 139 a-139 d to engage upon assembly, as describedin FIG. 9.

Although in FIG. 7 b, sleeve 114 is shown with four channels 139 a-139d, the present invention is not so limited. Sleeve 114 may include anynumber of channels, including as few as one channel.

FIG. 8 is a side view of first sleeve 112. First sleeve 112 includescuff 140, which is configured to fit inside second sleeve 114 whencenter connector 76 is assembled. As shown more clearly in FIG. 10, onceassembled, sleeves 112, 114 can be permanently attached at cuff 140, forexample by welding.

Preferably, a hard metal, such as titanium, is used to construct sleeves112, 114 because use of a hard material prevents binding within thejoints when the center section is fully assembled.

FIG. 9 shows a cross sectional view of an assembled articulated centersection combining the first embodiment of a center post withrotation-inhibiting capabilities and the first embodiment of a sleeve ofa center connector with rotation-inhibiting capabilities. Shown is knob24, first center post 72, second center post 74, center connector 76,holes 80, first sleeve 112, second sleeve 114, head 120, first neck 122,body 124, second neck 126, head 130, neck 132, body 134, pegs 138 a and138 c, channels 139 a-139 c, cuff 140, first socket 152, and secondsocket 154. Sleeves 112, 114 have been welded together to form centerconnector 76. Pegs 138 b and 138 d, and channel 139 d cannot be seen inthis view.

FIG. 10 is a sectional view of the first embodiment of the centersection along section 10-10 of FIG. 9 showing the interaction betweenpegs 138 a-138 d located on head 120 and channels 139 a-139 d locatedwithin socket 152 of sleeve 114. Shown is head 120, pegs 138 a-138 d,sleeve 114, channels 139 a-139 d, and socket 152.

Socket 152 of sleeve 114 houses head 120. Pegs 138 a-138 d located onhead 120 engage channels 139 a-139 d located within socket 152. Whileshown with respect to head 120 and sleeve 114, as shown in FIG. 9, head130 and sleeve 112 interact similarly.

To assemble the center section, center posts 72, 74 are slipped intocorresponding sleeves 112, 114. As described above with respect to FIGS.5 a and 6, the diameter of each head 120, 130 is less than the diameterof each body 124, 134. As a result, bodies 124, 134 are small enough tofit through sockets 152, 154 but heads 120, 130 are too large to fitthrough sockets 152, 154. When center post 72 is slipped through socket154 of sleeve 112, body 134 extends out through socket 154. Head 130remains inside sleeve 112. Similarly, once center post 74 is placedthrough socket 152 of sleeve 114, body 124 extends out through socket152. Head 120 remains inside sleeve 114.

When inserting center posts 72, 74 into sleeves 112, 114, pegs 138 a-138d and channels 139 a-139 d must be correlated to each other. Prior toinsertion into sleeve 112, center post 72 should be rotated so that pegs138 a-138 d on head 130 are positioned to slide into correspondingchannels 139 a-139 d located within socket 154. Likewise, prior toinsertion into sleeve 114, center post 174 should be rotated so thatpegs 138 a-138 d on head 120 are positioned to slide into correspondingchannels 139 a-139 d located within socket 152. Center posts 72, 74 arethen inserted into sleeves 112, 114 by sliding pegs 138 a-138 d intocorresponding channels 139 a-139 d until necks 122, 132 extend out ofsockets 152, 154. Finally, sleeve 112 and sleeve 114 are joined byinserting cuff 140 into sleeve 114, which comprises central connector76. Once assembled, sleeves 112, 114 may be welded together.

The resulting assembly forms two ball and socket joints, which are ableto articulate (i.e. pivot) but are rotationally inhibited. As describedabove, pegs 138 a-138 d and channels 139 a-139 d engage. Since pegs 138a-138 d of heads 120, 130 are housed within channels 139 a-139 d ofsleeves 112, 114, the rotational movement of center posts 72, 74 withrespect to central connector 76 is prevented. In other words, centerposts 72, 74 are prevented from turning around an axis extending throughsockets 152, 154. As previously described, preventing rotation of centerposts 72, 74 in relation to sleeves 112, 114 improves the overallpositioning of the device. It also is easier to distinguish individualoccluder elements, and the preliminary loading of the occlusion deviceinto a catheter may be simplified.

In order for the occlusion device to adequately conform to the walls ofthe heart, flexibility of the device is still needed. In thisembodiment, the interaction between pegs 138 a-138 d and channels 139a-139 d still permits articulated movement of center posts 72, 74.Center posts 72, 74 are able to pivot with respect to center connector76, while pegs 138 a-138 d and channels 139 a-139 d remain engaged.Because the center section retains the desired flexibility, an occlusiondevice will have the ability to match the contours of a heart. Thisresults in an increased life for the device, and also improves itssealing ability.

FIG. 11 is a perspective side view of a second embodiment of a centerpost with rotation-inhibiting capabilities. Shown is knob 24, centerpost 74, holes 80, head 120, first neck 122, body 124, second neck 126,and channels 139 a-139 b.

In this embodiment, head 120 includes channels 139 a-139 b locatedconcentrically around the rounded surface of head 120. Channels 139a-139 b may be evenly spaced to provide better articulation when coupledwith a center connector, as described in FIG. 12. Center post 74 ispreferably formed of a hard metal, such as titanium. Channels 139 a-139b may be machined directly into the titanium, using a process such aselectrical discharge machining.

Although in FIG. 11, head 120 is shown with two channels 139 a-139 b,the present invention is not so limited. Head 120 may include any numberof channels 139 a-139 b, including as few as one channel 139 a-139 b. Inaddition, while this embodiment is shown with respect to center post 74,which includes second neck 126 and knob 24, channels 139 a-139 b may beadded to a center post that does not include these features, as shownwith respect to center post 72 in FIG. 12.

FIG. 12 shows a cross sectional view of an assembled articulated centersection combining the second embodiment of a center post withrotation-inhibiting capabilities and the second embodiment of a sleeveof a center connector with rotation-inhibiting capabilities. Shown isknob 24, first center post 72, second center post 74, center connector76, holes 80, first sleeve 112, second sleeve 114, head 120, first neck122, body 124, second neck 126, head 130, neck 132, body 134, pegs 138 aand 138 c, channels 139 a-139 b, cuff 140, first socket 152, and secondsocket 154. Sleeves 112, 114 have been welded together to comprisecenter connector 76. Peg 138 b and peg 138 d cannot be seen from thisperspective.

FIG. 13 is a sectional view of the first embodiment of the centersection along section 13-13 of FIG. 12 showing the interaction betweenpegs 138 a-138 d located within socket 152 of sleeve 114 and channels139 a-139 b located on head 120. Shown is sleeve 114, head 120, pegs 138a-138 d, channels 139 a-139 b, and socket 152.

Socket 152 of sleeve 114 houses head 120. Pegs 138 a-138 d locatedwithin socket 152 engage channels 139 a-139 b located on head 120. Whileshown with respect to head 120 and sleeve 114, as shown in FIG. 12, head130 and sleeve 112 interact similarly.

To assemble the center section, center posts 72, 74 are slipped intocorresponding sleeves 112, 114. As described above with respect to FIGS.5 a and 6, the diameter of each head 120, 130 is less than the diameterof each body 124, 134. As a result, bodies 124, 134 are small enough tofit through sockets 152, 154 but heads 120, 130 are too large to fitthrough sockets 152, 154. When center post 72 is slipped through socket154 of sleeve 112, body 134 extends out through socket 154. Head 130remains inside sleeve 112. Similarly, once center post 74 is placedthrough socket 152 of sleeve 114, body 124 extends out through socket152. Head 120 remains inside sleeve 114.

When inserting center posts 72, 74 into sleeves 112, 114, pegs 138 a-138d and channels 139 a-139 b must be correlated to each other. Prior toinsertion into sleeve 112, center post 72 should be rotated so thatchannels 139 a-139 b on head 130 are positioned to slide ontocorresponding pegs 138 a-138 d located within socket 154. Likewise,prior to insertion into sleeve 114, center post 174 should be rotated sothat channels 139 a-139 b on head 120 are positioned to slide ontocorresponding pegs 138 a-138 d located within socket 152. Center posts72, 74 are then inserted into sleeves 112, 114 by sliding pegs 138 a-138d into corresponding channels 139 a-139 b until necks 122, 132 extendthrough sockets 152, 154. Finally, sleeve 112 and sleeve 114 are joinedby inserting cuff 140 into sleeve 114, which comprises central connector76. Once assembled, sleeves 112, 114 may be welded together.

The resulting assembly forms two ball and socket joints, which are ableto articulate but are rotationally inhibited. As described above, pegs138 a-138 d and channels 139 a-139 b engage. Since pegs 138 a-138 d ofsleeves 112, 114 are housed within channels 139 a-139 b of heads 120,130, the rotational movement of center posts 72, 74 with respect tocentral connector 76 is prevented. In other words, center posts 72, 74are prevented from turning around an axis extending through sockets 152,154. As previously described, preventing rotation of center posts 72, 74in relation to sleeves 112, 114 improves the overall positioning of thedevice. It also is easier to distinguish individual occluder elements,and the preliminary loading of the occlusion device into a catheter maybe simplified.

In order for the occlusion device to adequately conform to the walls ofthe heart, flexibility of the device is still needed. In thisembodiment, the interaction between pegs 138 a-138 d and channels 139a-139 b still permits articulated movement of center posts 72, 74.Center posts 72, 74 are able to pivot with respect to center connector76, while pegs 138 a-138 d and channels 139 a-139 b remain engaged.Because the center section retains the desired flexibility, an occlusiondevice will have the ability to match the contours of a heart. Thisresults in an increased life for the device, and also improves itssealing ability.

Though shown in a patent foramen ovale occlusion device, an articulatedcenter post can be adapted for use in any occluding device, includingthose designed for atrial septal defects, patent ductus arteriosus, andventricular septal defects. The center section can also be adapted foruse in an septal stabilization device.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention. In particular, any of the applicablefeatures disclosed in related applications U.S. patent applicationentitled Septal Stabilization Device, Ser. No. 10/349,744, U.S. patentapplication entitled Hoop Design for Occlusion Device, Ser. No.10/349,118, Occlusion Device Having Five or More Arms, Ser. No.10/348,701, and U.S. patent application entitled Laminated Sheets forUse in a Fully Retrievable Occlusion Device, Ser. No. 10/348,864, filedon even date herewith, may be of use in the present invention. Each ofthese applications is hereby incorporated by reference.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

1. An occlusion device comprising: a first occluding body; a secondoccluding body; and a center section including a ball and socket jointand means for limiting rotation of the first occluding body relative tothe second occluding body.
 2. The occlusion device of claim 1 whereinthe means for limiting rotation of the first occluding body relative tothe second occluding body includes interlocking elements.
 3. Theocclusion device of claim 2 wherein the interlocking elements include apeg on a ball of the ball and socket joint and a groove on a socket ofthe ball and socket joint.
 4. The occlusion device of claim 2 whereinthe interlocking elements include a groove on a ball of the ball andsocket joint and a peg on a socket of the ball and socket joint.
 5. Anocclusion device comprising: a first collapsible support frame; a secondcollapsible support frame; a first center support having a first body, afirst neck, and a first head, the first body connected to the firstcollapsible support frame; a second center support having a second body,a second neck, and a second head, the second body connected to thesecond collapsible support frame; a center connector providing anarticulated connection between the first center support and the secondcenter support, the center connector including a first socket in whichthe first head is movable and a second socket in which the second headis movable; a first sheet attached to the first collapsible supportframe; means for preventing rotation of the first head in the firstsocket; and means for preventing rotation of the second head in thesecond socket.
 6. The occlusion device of claim 5 and furthercomprising: a second sheet attached to the second collapsible supportframe.
 7. The occlusion device of claim 5 wherein each of the first andsecond collapsible support frames includes a plurality of arms.
 8. Theocclusion device of claim 7 wherein the first collapsible support frameis oriented relative to the second collapsible support frame to offsetthe arms of the first collapsible support frame from the arms of thesecond collapsible support frame.
 9. The occlusion device of claim 5wherein the center connector includes a first sleeve and a secondsleeve.
 10. The occlusion device of claim 9 wherein the first sleevecontains the first socket.
 11. The occlusion device of claim 10 whereinthe second sleeve contains the second socket.
 12. The occlusion deviceof claim 11 wherein the first sleeve and second sleeve connect to eachother.
 13. The occlusion device of claim 5 wherein the means forpreventing rotation of the first head in the first socket includes achannel in the first socket.
 14. The occlusion device of claim 13wherein the means for preventing rotation of the first head in the firstsocket further includes a peg on the first head that is movable in thechannel in the first socket.
 15. The occlusion device of claim 5 whereinthe means for preventing rotation of the second head in the secondsocket includes a channel in the second socket.
 16. The occlusion deviceof claim 15 wherein the means for preventing rotation of the second headin the second socket further includes a peg on the second head that ismovable in the channel in the second socket.
 17. The occlusion device ofclaim 5 wherein the means for preventing rotation of the first head inthe first socket includes a peg in the first socket.
 18. The occlusiondevice of claim 17 wherein the means for preventing rotation of thefirst head in the first socket further includes a channel on the firsthead for receiving the peg in the first socket.
 19. The occlusion deviceof claim 5 wherein the means for preventing rotation of the second headin the second socket includes a peg in the second socket.
 20. Theocclusion device of claim 19 wherein the means for preventing rotationof the second head in the second socket further includes a channel onthe second head for receiving the peg in the second socket.
 21. A centerconnection for an occlusion device, the center connection comprising: afirst center post having a first body, a first neck, and a first head; asecond center post having a second body, a second neck, and a secondhead; and a center connector that engages the first head and the secondhead to permit articulated movement of the first and second center postswhile preventing rotational movement of the first and second centerposts with respect to the center connector.
 22. The center connection ofclaim 21 wherein the center connector further comprises a first sleeveand a second sleeve.
 23. The center connector of claim 22 wherein thesecond sleeve has a cuff at a proximal end for attachment to the firstsleeve.
 24. The center connection of claim 22 wherein the centerconnector includes a peg.
 25. The center connection of claim 22 whereinthe first and second heads each comprise a channel which receives a pegon the center connector.
 26. The center connection of claim 22 whereinthe center connector includes a channel.
 27. The center connection ofclaim 22 wherein the first and second heads each include a peg whichengages a channel on the center connector.